Standard for espresso bean grind fineness How to determine espresso grind powder-water ratio

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Many friends reported that they bought Italian coffee beans and went back to grind them. After extraction, there was no way to extract the oil. The concentrated oil extracted was tasteless on the whole and felt like water. When this problem occurs, the baristas on the front street will suggest adjusting the degree of grinding. This article will talk about how to determine the grindability of espresso.

First of all, before we adjust the grinding degree, we should choose freshly roasted Italian coffee beans.

First of all, the selection of products should be clearly marked with the baking date (not the effective date or shelf life), brand reputation, emphasis on fresh roasting professional coffee roasters to choose and buy.

In addition, excellent coffee bags are usually designed with a "one-way exhaust valve" (a button-shaped hole in the top of the coffee bag) for coffee beans to discharge naturally occurring carbon dioxide. Point the one-way exhaust valve at the nose, gently squeeze the coffee bag and smell the gas. If it is a charming and fragrant coffee aroma, the freshness is not a problem. On the contrary, if it does not smell strong enough, or even smells of smelly oil, it means that this bag of coffee has already gone bad and should be avoided. Every packet of coffee beans sold in Qianjie Coffee is packaged with an one-way exhaust valve to ensure that each packet of coffee beans is in the freshest state to the buyer.

Choose a grinder that can grind espresso powder

For commercial use, you can buy Italian bean grinders. The most important feature of the Italian bean grinder is that the grinding is very fine, the speed is fast, and the knife head is large, and the uniformity is a hard index to judge whether the coffee grinder is easy to use, while the Italian bean grinder is usually not as fine as that of the Italian bean grinder. If the family uses the grinding degree that we want to get to the espresso powder, we have to choose a flat knife bean grinder. Qianjie Coffee currently uses Pegasus 600N flat knife grinder to grind espresso coffee powder.

Why does Qianjie Association recommend the grinder with flat knife?

The working principle of the flat knife grinder: it is composed of the upper and lower cutter heads, and the base is fixed on the motor. When the motor starts, it rotates the upper and lower cutter heads to produce cutting action. When the coffee particles fall from the middle, the knife head rotating at the bottom will spin the coffee beans to the outside and push the coffee beans into the tooth cutter part for grinding. The upper and lower cutters of the flat knife are placed in a parallel manner, so the coffee beans need to rely on the rotating force of the bottom cutterhead to push the coffee beans into the cutterhead, so the weight of the coffee beans placed on the top will affect the uniformity of the coffee beans entering the knife cutter. in addition, due to pushing, the number of collisions between coffee beans increases, resulting in an increase in the proportion of fine powder. This is the reason why the particle uniformity of the common flat knife bean grinder is slightly worse and the fine powder is more. Increase the concentration and extraction rate of coffee in a short time, so that the aroma of coffee can be significantly improved in a short time.

The flat knife grinder has the advantages of clear positioning, the quality of the product is proportional to the grade of the bean grinder and the diameter of the grinding plate: disadvantages: the uniformity of the grinding particles is slightly worse, and the fine powder is more, because the blade of the flat knife grinder cuts coffee beans at will, which can easily lead to insufficient or excessive extraction of coffee powder in brewing. In addition, flat knife friction will generate heat, especially when the flat knife grinder works for a long time. It will have an obvious charred and bitter taste.

The grinding principle of the bean grinder?

When the coffee bean enters the grinder, the blade in the grinder will crush the coffee bean into powder. The smaller the distance between the blade and the blade, the smaller the coffee beans will be ground into smaller particles. The finer the grinding particles are, the tighter they are, and the more difficult it is for the water to pass through, thus greatly prolonging the extraction time. On the contrary, if the distance between the blades increases, the ground particles will become rougher, the flow of water will be easier to pass through, and the extraction time will be faster.

How can we determine the degree of grinding that is suitable for our concentrator?

Qianjie in adjusting the grinding degree will first use the concentrated extraction gold ratio and golden time to set a parameter: 1:2 ratio (20g powder extraction 40ml coffee liquid) extraction time between 25 and 28 seconds, and then through observation and taste to determine the adjustment of the grinding degree.

If the grinding degree is too rough, the water will flow through the powder bowl too fast, the water flow is thick, the extraction is light, the color of the oil is white and the flavor is sharp, because the extraction is incomplete, only the surface and acid substances that are easy to extract are extracted.

The grinding degree is too fine, first of all, it will clog the filter hole, the water can not flow out or the water column is too thin, the color of the oil is dark, and it will be over-extracted on the surface, which is sharp and sour, because of the lack of sweetness, and then it will be bitter and smelly.

If you want to test whether the concentration reaches the standard value more strictly, we can first calibrate the concentration tester. Most of the espresso concentrations are between 7% and 12%. Clear the zero standard with pure water. Then stir the extracted hand coffee, and use the titration test tube to extract the coffee liquid, put it into the coffee concentration tester, press the determination key, try to determine the value many times, until the value is stable.

Extraction parameters of espresso from Qianjie Coffee

Qianjie Coffee is currently making espresso using a blend of beans treated in sherry buckets and sun-treated Yegashifi red cherries. 60% of the Honduran sherry barrel coffee beans provide flavor and mellow thickness for this blend, while 40% of the sun-tanned Yega Chevy coffee beans provide more aroma and acidity.

Qianjie concentrated extraction parameters:

Grinder: Pegasus 900N

Degree of grinding: 1.6

Pressure: 9 bar ±2

Temperature: 90.5 ~ 96 °C

Time: 20: 30 s

Powder content: 20g (double espresso)

Amount of extraction: 40ml extract espresso flavor: smooth taste, medium alcohol thickness, entrance with obvious acidity accompanied by a hint of berry aroma, whisky, strong chocolate flavor.

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